Although, the curious part for me is why they decided to go back, throughout all their history, and edit every single post.
He came to the forum after 2 years and sat on the forum for two whole days and edited all his posts.

Probably he is trying to erase his traces of what he said and did here on the forum.
But, if you forgot or don't know, there are several sites that scrape the forum and keep all this history, even if the posts are edited.
The problem is when moderation is based on the common sense of each moderator. And in turn, there are no criteria for reporting posts. Each one does it based on their common sense and their notion of what is of value or not.
I made a few reports, but still about 15% of the reports were not accepted. And I am aware that everything I reported was clearly spam or something that was not in the right place. How is this possible? I don't know...
I have to take the time to look at that list and understand what wasn't accepted... (where do I see that again?)